Tthe G16 database has been replaced by new version and is now containing colour information from the Gaia DR2 .
To make it work you have to download the latest HNSKY version 4.0.0L and new G16 database.
The magnitudes in the G16 are the calculated Johnson-V and the colour information is the Gaia Blue (Bp) minus Gaia red (Rp) magnitudes.
If there is no colour information, the stars are green coloured. The star colouring is currently fixed at:
<-0.25 => blue
-0.25 tot -0.1 => cyan
-0.1 tot 0.3 => white
0.3 tot 0.7 => yellow white
0.7 tot 1.0 => yellow
1.0 tot 1.5 => orange
>1.5 => red
No info => green